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Re: Different answers in mathematica and my calculator.

• To: mathgroup at smc.vnet.net
• Subject: [mg125610] Re: Different answers in mathematica and my calculator.
• From: DrMajorBob <btreat1 at austin.rr.com>
• Date: Wed, 21 Mar 2012 05:47:34 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com

-1 is a real cube root of -1, so it's not quite correct to say "(-1)^(1/3)  
is complex".

Two cube roots of -1 ARE complex, of course.

Bobby

On Tue, 20 Mar 2012 02:21:56 -0500, psycho_dad <s.nesseris at gmail.com>  
wrote:

> I'm afraid that Sec corresponds to 1/Cos in the sense of 2 and 1/2  
> respectively. The function you want is ArcCos (inverse cosine).
>
> As for the first question, mathematica is right, so you are either doing  
> something wrong on the calculator or it doesn't support complex numbers,  
> as Power[2(-2)+3, (3)^-1]=(-1)^(1/3) is complex.
>


-- 
DrMajorBob at yahoo.com

• Follow-Ups:
  • Re: Different answers in mathematica and my calculator.
    • From: Murray Eisenberg <murray@math.umass.edu>